Thursday, May 2, 2013

A paper published today in the Journal of Geophysical Research - Atmospheres finds tiny changes in solar activity during 11-year solar cycles have large, amplified effects on the winter climate of East Asia by modulating the impact of the El Nino Southern Oscillation [ENSO]. According to the authors, "The results indicate that the ENSO and East Asian climate relationship is robust and significant during winters with low solar (LS) activity, with evident warming in the lower troposphere over East Asia." The authors also find changes in precipitation related to solar activity and that "Further investigation with long historic data confirms that the relationship between the ENSO and the East Asian winter climate anomalies depends on the phases of 11-year solar cycle, with enhanced East Asian climate variation during the LS [low solar] winters." The IPCC claims the 0.1% variation in total solar irradiance during solar cycles cannot affect climate, but this paper and many others confirm that tiny variations in solar activity can have large, amplified effects on climate via modulation of ocean & atmospheric oscillations such as ENSO, the Arctic Oscillation, Madden-Julian oscillation, and Quasi-biennial oscillation, as well as via stratospheric ozone and sunshine hours/clouds.

Abstract

This study examines how the East Asian winter climate response to the El Niño-Southern Oscillation (ENSO) varies with the 11-year solar cycle.The results indicate that the ENSO and East Asian climate relationship is robust and significant during winters with low solar (LS) activity, with evident warming in the lower troposphere over East Asia, which can be closely linked to the decreased pressure gradient between the cold Eurasian continent and the warm Pacific. Moreover, during the LS and El Niño winters there is a typical rainfall response in Southeast Asia, with wet conditions over South China and dry conditions over the Philippines, Borneo, Celebes, and Sulawesi, which can be explained by the anticyclone over the western North Pacific (WNP). However, during high solar (HS) activity winters, both the surface temperature and rainfall anomalies are much less closely associated with the ENSO. The possible mechanism for this solar modulation of the ENSO-related East Asian climate anomalies may be the change in the tropospheric circulation with the ENSO in both tropical and extratropical regions. Particularly, in the LS cases an anomalous WNP anticyclone is intensified and a noticeable cyclone occupies northern Northeast Asia, resulting from the changing location and strength of the large-scale Walker circulation induced by the more pronounced sea surface temperature (SST) anomalies associated with the ENSO. Further investigation with long historic data confirms that the relationship between the ENSO and the East Asian winter climate anomalies depends on the phases of 11-year solar cycle, with enhanced East Asian climate variation during the LS winters.